Evaluation of DSP based Numerical Relay for Overcurrent Protection

Abstract

The reliability and security electrical supply is an important factor in modern society. However, the increasing complexity of power systems makes it difficult for protection operation to achieve these objectives. Nevertheless, numerical relays embedded with digital signal processor (DSP) are able to improve the protection operation significantly. The relays are capable of performing complex processing faster and with higher accuracy since the processing using DSP are optimized for real-time signal processing. In this paper, an overcurrent relay is built and investigated using DSP, TMS320F2812. The overcurrent protection is chosen since it is used as a major protection in the distribution systems. The overcurrent relay is modeled in MATLAB/Simulink before it is implemented on the DSP. Comparison results between simulation and hardware execution based on two implementation methods are presented. The performance evaluation of the relay in terms of operation time, memory capacity usage, execution time and transient analysis is investigated.